An “unidentified object” was shot down with a missile by US fighter jets on Sunday over Lake Huron, and it was believed to be the same one tracked over Montana and monitored by the government beginning the night before, US officials said.

The downing comes after earlier objects in Alaska and Canada were shot out of the sky because they were flying at altitudes that posed a threat to commercial aircraft, according to the officials.

It was extraordinary that four objects were shot out of the sky by US fighter jets in eight days.

Pentagon officials have said they do not know when the last shootdown of an unknown or unauthorised object over US territory occurred.

The latest object brought down was first detected on Saturday over Montana, but it was initially thought to be an anomaly.

Radar picked it up again Sunday hovering over the Upper Peninsula of Michigan and it was going over Lake Huron.

US and Canadian authorities earlier on Sunday restricted some airspace over the lake, near the Canadian border, as aircraft were scrambled to intercept and try to identify the object.

Congresswoman Elissa Slotkin tweeted that “the object has been downed by pilots from the US Air Force and National Guard”.

The shootdown was confirmed by four US officials.

The news comes as US officials were still trying to precisely identify the other two objects blown from the sky by F-22 fighter jets over the past two days, and were working to determine whether China was responsible, as concerns escalate about what Washington says is Beijing’s large-scale aerial surveillance programme.

United States Aerial Objects
A high-altitude surveillance balloon is recovered off the coast of Myrtle Beach, South Carolina (US Navy/AP)

The object shot down Saturday over the Yukon was described by US officials as a balloon significantly smaller than the one hit by a missile on February 4 while drifting off the South Carolina coast after traversing the country.

A flying object brought down over the remote northern coast of Alaska on Friday was more cylindrical and described as a type of airship.

Both were believed to have a payload, either attached or suspended from them, according to the officials.

Officials were not able to say who launched the objects and were trying to establish their origin.

US officials said the two more recent objects were much smaller in size, different in appearance and flew at lower altitudes than the suspected Chinese spy balloon that fell into the Atlantic after the US missile strike.

United States Aerial Objects
The Biden administration says it was a surveillance operation that took the Chinese balloon near US military sites (US Navy/AP)

They said the Alaska and Canada objects were not consistent with the fleet of Chinese aerial surveillance balloons that targeted more than 40 countries, stretching back at least into the Trump administration.

That large white orb first appeared over the US in late January, and since then Americans have been fixated on the sky above them.

US authorities made clear that they constantly monitor for unknown radar blips, and it is not unusual to shut down airspace as a precaution to evaluate them.

On Sunday the US briefly closed the airspace over Lake Michigan and on Saturday night over rural Montana.

Officials Sunday said they were no longer tracking any objects over those locations.